Seafloor features are revealed by the gravity field

From NASA

It has been said that we have more complete maps of the surface of Mars or the Moon than we do of Earth.
Close to 70 percent of our planet is covered by water, and that water refracts, absorbs, and reflects light so well that it can only penetrate a few tens to hundreds of meters.
To humans and most satellite eyes, the deep ocean is opaque

But there are ways to visualize what the planet looks like beneath that watery shroud.
Sonar-based (sounding) instruments mounted on ships can distinguish the shape (bathymetry) of the seafloor.
But such maps can only be made for places where ships and sonar pass frequently.
The majority of such measurements have been made along the major shipping routes of the world, interspersed with results from scientific expeditions over the past two centuries.
About 5 to 15 percent of the global ocean floor has been mapped in this way, depending on how you define “mapped.”

There is another way to see the depths of the ocean: by measuring the shape and gravity field of Earth, a discipline known as geodesy.
David Sandwell of the Scripps Institution of Oceanography and Walter Smith of the National Oceanic and Atmospheric Administration have spent much of the past 25 years negotiating with military agencies and satellite operators to allow them acquire or gain access to measurements of the Earth’s gravity field and sea surface heights.
The result of their collaborative efforts is a global data set that tells where the ridges and valleys are by showing where the planet’s gravity field varies.
The map above shows a global view of gravity anomalies, as measured and assembled by Sandwell, Smith, and colleagues.
Shades of orange and red represent areas where seafloor gravity is stronger (in milligals) than the global average, a phenomenon that mostly coincides with the location of underwater ridges, seamounts, and the edges of Earth’s tectonic plates.
Shades of blue represent areas of lower gravity, corresponding largely with the deepest troughs in the ocean.
The second map shows a tighter view of that data along the Mid-Atlantic Ridge between Africa and South America.

The maps were created through computer analysis and modeling of new satellite altimetry data from the European Space Agency’s CryoSat-2 and from the NASA-CNES Jason-1, as well as older data from missions flown in the 1980s and 90s.
CryoSat-2 was designed to collect data over Earth’s polar regions, but it also collected measurements over the oceans.
Jason-1 was specifically designed to measure the height of the oceans, but it had to be adjusted to a slightly different orbit in order to acquire the data needed to see gravity anomalies.
But how does the height of the sea surface (which is what the altimeters measured) tell us something about gravity and the seafloor?
Mountains and other seafloor features have a lot of mass, so they exert a gravitational pull on the water above and around them; essentially, seamounts pull more water toward their center of mass. This causes water to pile up in small but measurable bumps on the sea surface.
(If you are wondering why a greater mass would not pull the water down, it is because water is incompressible; that is, it will not shrink into a smaller volume.)
The new measurements of these tiny bumps on the sea surface were compared and combined with previous gravity measurements to make a map that is two-to four times more detailed than before. Through their work, Sandwell, Smith, and the team have charted thousands of previously uncharted mountains and abyssal hills.
The new map gives an accurate picture of seafloor topography at a scale of 5 kilometers per pixel.

From these seafloor maps, scientists can further refine their understand of the evolution and motion of Earth’s tectonic plates and the continents they carry.
They can also improve estimates of the depth of the seafloor in various regions and target new sonar surveys to further refine the details, especially in areas where there is thick sediment.
This third map shows the gravity data as a cartographer would represent the seafloor, with darker blues representing deeper areas.

Links :

• Sandwell, D. et al. (2014) New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure. Science, 346 (6205), 65–67.
• Scripps Institution of Oceanography (2014, October 2) Marine Gravity from Satellite Altimetry. Accessed December 23, 2015.
• Scripps Institution of Oceanography (2014, October 2) New Map Exposes Previously Unseen Details of Seafloor. Accessed December 23, 2015.
• Carlowicz, M. (1995, October 31) New Map of Seafloor Mirrors Surface. EOS, Transactions, AGU, 441–442.
• University of Sydney (2014, October 5) Mapping the Seafloor from Space. Accessed December 23, 2015.
• Scientific American (2014, October 9) Just How Little Do We Know about the Ocean Floor? Accessed December 23, 2015.
• Schmidt Ocean Institute (2013, March 12) The Ocean: Haven’t We Already Mapped It? Accessed December 23, 2015.
• NOAA National Ocean Service (2015) What is geodesy? Accessed December 23, 2015.
• NOAA National Ocean Service (2015) How much of the ocean have we explored? Accessed December 23, 2015.
• DailyMail : The most accurate ocean floor map ever made: Scientists reveal the alien landscape beneath the sea in incredible detail
  

Why are sea levels dropping in places closest to the melting glaciers?

Global rebound rates as the world adjusts from the last ice age.

Image credit: A. Paulson/S. Zhong/J. Wahr

From io9 by Mika McKinnon

Our dynamic planet has an apparent paradox: the more ice melts from landlocked glaciers, the lower the sea level gets in nearby areas.
How does this happen?
Through the physics of isostatic rebound, when the surface of the planet acts as an elastic sheet dimpling and rebounding under changing loads.

Perito Moreno Glacier in Argentina is one of the few terrestrial glaciers advancing in modern times. Image credit: Frank Kehren

Rocks seem so very solid from our puny human perspective.
Things are rock hard, rock solid, and are reliable as the rock itself.
But from a geological perspective, rock is an elastic sheet that encompasses our planet in a thin, flexible membrane that responds to every disturbance.

Nowhere is this more evident than with isostatic rebound, a process of geological buoyancy by which the earth's crust, having sunk beneath the weight of glaciers from a preceding ice age, bounces up as ice sheets melt and the water runs back into the sea.
While this melting ice is filling the oceans, the land can rebound so quickly that it rises even faster than the climbing sea level.
The result is an apparent paradox: where continental glaciers are melting and exposing the land, the local sea levels are dropping.

The Thwaites ice shelf in Antartica as surveyed in October 2013 by Operation IceBridge. 

Image credit: James Yungel/NASA

During each ice age, massive glaciers crawl across the land.
These vast ice sheets contain an enormous quantity of water.
And water is very, very heavy.

The crust and mantle deform under the weight of ice sheets.

Image modified from NASA

During the last ice age 15,000 to 20,000 years ago, Canada and the United States were groaning under the weight of the Laurentide and Cordilleran ice sheets while Scandinavia struggled under the Fennoscandian ice sheet.
The Earth's lithosphere, the rigid crust and uppermost mantle, buckled under the weight of up to 3 kilometers of ice.
Like an iceberg floating in water with a vast root hidden under the waves, the crust sank into the mantle until hitting a buoyant balance between the weight of ice and rock over hot mantle.
Kept under load for thousands of years, the lithosphere flowed and deformed to reach equilibrium under the new normal.

When the world shook off the ice age, the ice sheets melted quickly.
The land was bare in a geologic heartbeat, lifting the weight far, far faster than it built up millennia before.
The elastic crust rebounded nearly instantaneously, bouncing back like a balloon's surface freed from an aggressive squeeze.
But the more viscous mantle was slower to reach equilibrium in the new isostatic regime, driving slow uplift as the mantle flowed under the dented land.
The rebound is ongoing today, with the land recovering at centimetres per year.
With the rebound rates akin to the speed at which fingernails grow, it will take another 10,000 years before the land recovers from the last ice age.

The same story is happening everywhere that was covered in ice: the lithosphere buckled under the massive weight of ice sheets, and has been slowly recovering in the millennia since they were exposed.
From the Antarctic still shedding weight to Canada's Hudson Bay racing upwards at nearly 2 centimeters per year, the surface of our planet is literally reshaping beneath our feet.
For people in the far north and south of our planet, every time they trim their nails they can reflect on how much higher their home has bounced since the last manicure.

As the lithosphere rebounds, it carries the entire landscape with it.
Sea cliffs and rivers are stranded far above their formation location, and strandlines of past beaches are laid out in beautiful, delicate features tracing sea levels long gone.
Even the tilt of the land changes: drainage patterns struggling to adjust to keep water flowing downhill.

A stranded river cuts a new waterfall as the land rebounds above the sea in Alaska

Image credit: Jim & Laura Massie

The arrival and release of weight impacts the stress of the entire region, potentially triggering earthquakes and volcanoes.
Before fracking and injection wells made a mess of the continental interior, the biggest causes of intraplate earthquakes far from plate tectonic boundaries were attributed to the shifting stresses of isostatic rebound.
These impacts can be far-reaching in both space and time: despite being ice-free, the infamous 1811 New Madrid earthquake in the American south may have been induced by intraplate stresses induced from the last ice age.

The same thing is happening for volcanoes.
A key trigger of eruptions is changing in the subsurface pressure and stress adjustments in the magma chamber.
As the lithosphere flexes and recovers, this redistribution can be enough to fuel a surge in volcanic activity.
Right now, the released pressure in Iceland could be fuelling a surge in volcanism, magma chambers long kept confined expanding and pushing out into surface eruptions from the flight-disrupting Eyjafjallajökull to the ongoing slow, steady trickle of Bárðarbunga.

The Bárðarbunga eruption in Iceland is spilling across the country's terrestrial glaciers.
Image credit: NASA

But most fascinatingly of all, isostatic rebound is the secret process behind how locations can have sea levels changing at odds with the rest of the planet.
While we all know about global sea levels rising and falling, geologists also track local sea levels, the relative change in sea level at particular locations.

During an ice age, water once free to flood the oceans is tied up in continental ice sheets.
This drops global sea levels, exposing seafloor as the new coastline.
Yet the land with these new ice sheets is under load, dropping down relative to its former height.
Relatively speaking, despite the global sea levels falling, the local sea level can actually rise.

Right now, we're distinctly not in an ice age.
The land-bound glaciers are melting, and sea levels are rising from both the influx of released water and thermal expansion.
And yet, for the places suddenly relieved of their frozen load, the land itself is rebounding higher above the waves, maybe even faster than the grasping clutch of the sea.
Determining just how quickly each process is occurring is a jumbled mess of scrambling to monitor rapidly changing data to calibrate our models, but for now, parts of Iceland, Greenland, and Canada are climbing faster than their sea levels.
From the perspective of beach-side homes, the relative sea level is staying stagnant or even dropping while the rest of the world contends with higher storm surges and floods.

Strandlines mark the relative sea level change from isostatic rebound in Bathurst Inlet, Nunavut.
Image credit: Mike Beauregard

Isostatic rebound is just one example of how the surface of our planet is a dynamic, changeable place where the materials behave far differently in aggregate than we perceive them from our daily perspective.

Links :

• Gizmodo : Iceland Is Rising Out of the Water

GeoGarage accessible on iPhone/iPad with Weather 4D 2.0

Weather 4D 2.0 on the AppStore

with subscriptions to the GeoGarage platform

--> see GeoGarage blog News

Note : for Android users

Marine GeoGarage nautical charts platform accessible for Weather 4D Pro Android mobile app users

 

Links :

• GeoGarage blog : Charts subscription available for Weather 4D 2.0 on iPhone/iPad
• Fustier blog : Weather4D 2.0 revisits navigation on iPad / Buy charts on GeoGarage
• Vimeo : Videos from User Guide "Navigation & Weather routing"
• iBooks : Navigation et Routage méteo avec Weather 4D 2.0 (FR) / Navigation & Weather Routing with Weather4D 2.0 (US)
• Urbanbike : Avis de tempête avec Weather 4D (in French)

This Old Map: Benjamin Franklin's Gulf Stream, 1786

The  map 'Chart of the Gulf Stream' in an occasional series

depicts a turning point in transatlantic navigation.
Franklin, always an advocate of science and invention,
published this early map of the Gulf Stream in the Atlantic Ocean in 1786.
see Raremaps

From TheCityLab by Laura Bliss

Thanks to the jet stream, westbound flights across the Atlantic take longer than eastbound ones.
In the centuries before air travel, sailors dealt with a related time-sucking natural phenomenon, until a famous American intervened with “A Chart of the Gulf Stream.”

Who made this map?

Benjamin Franklin and his cousin, Timothy Folger, are credited with naming and mapping the Gulf Stream for the first time—the warm, strong ocean current that pushes northeast from the Gulf of Mexico, up the Atlantic coast, towards Europe.
Though there were many editions, the map pictured above was printed by the American Philosophical Society in 1786, and now belongs to the Library of Congress.

 Here is another chart from the pen of Benjamin Franklin.

It shows that he realized that the Gulf Stream is actually a loop.

Here is another chart from the pen of Benjamin Franklin. It shows that he realized that the Gulf Stream is actually a loop. - See more at: http://every-day-is-special.blogspot.fr/2011/05/may-2-2011-you-go-gulf-stream.html#sthash.cjsbbSuF.dpuf

What problem did it solve?

In 1768, Franklin was in London, working as deputy postmaster general for the American colonies.
A visit by Folger, who captained a merchant ship, prompted Franklin to inquire about something peeving him.
Why did it take British mail packet ships so much longer to reach America than it took regular merchant vessels?
It struck Folger that the British mail captains must not know about the Gulf Stream, with which he had become well-acquainted in his earlier years as a Nantucket whaler.

Franklin later quoted his cousin’s explanation like this:

We are well acquainted with that stream, says he, because in our pursuit of whales, which keep near the sides of it, but are not to be met with in it, we run down along the sides, and frequently cross it to change our side: and in crossing it have sometimes met and spoke with those packets, who were in the middle of it, and stemming it. We have informed them that stemming a current, that was against them to the value of three miles an hour; and advised them to cross it and get out of it; but they were too wise to be counselled by simple American fishermen.

In other words, westbound British packet ships were losing precious time by sailing into and against the warm, strong current.
Folger sketched out the rough location for Franklin, who soon made prints, along with his cousin’s directions for how to avoid what he dubbed the “Gulph Stream.”

Who used it?

Franklin passed out copies to those hapless British packet mariners, but again, they didn’t think much of the American’s sailing pointers, and apparently ignored them.

With the start of the American Revolution a few years later, Franklin’s allegiances shifted.
He stopped distributing the Gulf Stream map to the British, and instead gave copies to the French, who used it to ship weapons and supplies to their American allies.
After that, knowledge of the stream became “hugely important for transatlantic travel,” says Alex Clausen, a maps specialist at Swann Auction Galleries, where a copy of the map recently sold for about $8,000.

 Computer Model of the Gulf Stream Surface Temperature, 2005.

The Gulf Stream is not really a “river in the ocean” as Franklin thought.

But the waters that make up the Gulf Stream are “channeled” into a certain direction and speed by many factors-including prevailing winds, the rotation of the planet, and colder currents around and below the Gulf Stream.

source : Ocean currents, NOAA

Is it accurate?

Compare Franklin and Folger’s 18th-century chart to modern computer-generated models of the Gulf Stream, and they match up remarkably well.
While Franklin himself made observations of the stream on ocean voyages—“I find that it is always warmer than the sea on each side of it, and that it does not sparkle in the night”—the accuracy of the chart is really due to Folger and his inherited whaling knowledge.
Also, Spanish mariners had known about the Gulf Stream since the 1500s.
But Franklin was the one with the good instincts to map it, and that, combined with his general eminence, has landed him with most of the credit.

In 1854, Coast Survey showed the positions and comparisons of observations of temperature in the Gulf Stream 1845 through 1848, 1853 and 1854

(courtesy of NOAA historical)

More than two centuries after this chart was first published, Grumman Aerospace Corporation launched a landmark undersea expedition off the coast of Florida to study the depths of the Gulf Stream.
The submersible’s name? What else: the Ben Franklin.

Links :

• NOAA : Who first charted the Gulf Stream?
• GeoGarage blog : What is the Gulf Stream?
• io9 : Here's the earliest known map of the Gulf Stream, created by Benjamin Franklin 

Ocean solutions

From Le Monde Diplomatique by Torsten Thiele

In June 2015 the UN General Assembly approved a resolution to negotiate a new legally binding instrument to implement the UN Convention on the Law of the Sea.
We may hope this will pave the way for the creation of areas where marine biodiversity is rigorously protected by law, as well as more equitable access to the high seas and fairer sharing of their benefits, within a framework of shared governance.

This is just the start of what promises to be a lengthy process, but it represents a major shift in the international community’s attitude to the protection of the oceans.
It also signals the start of an era of real hope for a swift and effective end to the exploitation and degradation of the ocean that has characterized the last hundred years.
It is encouraging that private organizations are driving a vision for bigger ideas, new thinking and broader partnerships.

Private philanthropic initiatives can provide decisive support in the design and implementation of marine protected areas.
They offer a management framework that, by engaging local communities as well as scientists in the process should make it easier to overcome challenges and stay on course in the longer term.

Large, remote high seas ecosystems such as the Sargasso Sea are now recognised as key areas for protection, but by virtue of their size will require new forms of monitoring such as satellites, drones and unmanned marine vehicles.
These will deliver scientific research benefits as well as operational efficiencies.

Studies have shown the value of large no-take marine protected areas as carbon sinks (helping to prevent global warming) but also as breeding grounds for whales and dolphins.
The preservation of marine mammals is vital for the fishing and whale-watching sectors, and for global biodiversity.

It’s clear we need to think differently.
The ecological, scientific and legal arguments for ocean conservation are numerous and irrefutable, but they are not enough.
To be effective, they must be combined with new ideas, technologies and sources of finance suited to the task.

The creation of an “ocean bank for sustainability and development”, funded through a one-time equity investment by governments and private partners, could offer viable financing options for initiatives to promote the survival and regeneration of the oceans.

We also need to broaden our partnerships.
The Paris climate conference (COP 21) this month offers an opportunity to form alliances between professionals from different sectors united by their awareness of the importance of protecting marine biodiversity.
It’s high time we recognized that the oceans are not just a source of food and minerals for exploitation, but are also vital for the future of our planet and the survival of humanity.

Links :

• Le Monde Diplomatique : Global warming, actors and victims / Easter Island’s marine reserve /  Towards a ‘blue economy’ / Time for international rules

Oceans

Extract of the "Oceans" movie

Links :

• GeoGarage blog : Oceans film, a tradition of commitment to nature and the environment / Ocean planet, the movie / Word Ocean Day

Your guide to the Boxing Day Sydney to Hobart 2015 yacht race

www.rolexsydneyhobart.com

The Rolex Sydney Hobart Yacht Race, organised by the Cruising Yacht Club of Australia, is the ultimate test for skippers, tacticians and crews.

The 2015 race will be the 71st edition of this time-honoured event and see 110 yachts from 28 nations race more than 600 Nautical Miles in quest of the Tattersall’s Cup and to win the coveted Rolex timepiece.

From ABC & Courier Mail

All eyes will once again be on defending Sydney to Hobart line honours champion Wild Oats XI and American challenger Comanche when the annual Boxing Day race begins on Saturday.
This year's blue water classic is shaping up as a replay of last year's epic finish, when Australia's yachting sweetheart pipped her 100-foot rival by just 55 minutes to claim an unprecedented eighth title.

Fellow supermaxis Ragamuffin 100 and the celebrity-laden Perpetual Loyal will also contend for the coveted crown, as will another US raider in Rambler 88.

The Wild Oats XI preparation includes some serious testing of a radical, retractable hydrofoil-type wing that will extend 2.75 metres out from the hull on the leeward side to improve the yacht's downwind performance.
"It assists us more in surfing downwind, off the breeze, sailing mode"

But the focus will undoubtedly be on the two powerhouses at the starter's line on Boxing Day, just as it was last year when Comanche left Wild Oats XI skipper Mark Richards eating dust with a spectacular start.
Richards and his crew recovered to arrive first in Hobart, however owner Bob Oatley has since gone to great lengths to stay ahead of his American counterpart and the chasing pack.
A radical $2 million nose job has been the talk of the sailing community since Wild Oats XI went under the knife mid-year, although Richards said he held no fears she had lost any of her speed.

Two weeks ago she blew her opponents — minus Comanche — out of the water in the SOLAS Big Boat challenge and showed off some serious speed.
"There's absolutely no issues there at all. These guys have been building boats and been in the boating job for a long time. So we've got a lot of confidence there," Richards said.

The Wild Oats team have enjoyed a relaxed Christmas Day in comparison to last year, when they were forced into repairing a broken boom in the lead-up.
"Last year we had a few issues with a few bits and pieces which weren't prepared until Christmas Day," Richards said.
"So we were out there checking a few things on Christmas Day. It's a bit more relaxed this year.
"Whether it's a good sign or a bad sign, I'm not quite sure. But we'll see what happens."

In the handicap battle, Hobart debutant Chinese Whisper is the leading contender to take the crown off defending champion Wild Rose, who will also get stiff competition from Rambler 88 and Ichi Ban.

A is for armada: 109 yachts will race south in the 71st Sydney to Hobart. The first race in 1945 had just nine little yachts.

B is for bowmen/women: They’re in the firing line at the front of the boats. The wettest job in the game and one of its most dangerous because it involves working on a wildly bucking and very slippery platform

C is for clipper: Round the world yachts are using the Sydney to Hobart as a leg of their world odyssesy. A fleet of 12 of these yacht, many sailed by novices, are racing south. Aussie Wendy Tuck is one of the skippers.

D is for the Derwent Ririver. It’s where the race finishes between two and six days after it starts on December 26. The fickle winds on the river, which can shut down completely overnight, can turn the race upside down — and have done so on more than one occasion.

E is for emergency tiller: A small tiller that fits into the top of the rudder post which can be used to steer the boat if main wheel steering equipment fails. Crucial if boat is damaged.

Comanche Sails!! FAST!! from Onne van der Wal

F is for freeze dried food: Activated by water and used by some crews for convenience and to save on weight. Not a favourite of sailors but does the job.

G is for gunwale. The rail that sticks up at the edge of the deck; as in walking on deck feels more secure if there is a gunwale.

H is for hot bunking: Where one crew gets up to go on watch and his/her warm bunk spot is taken by another. Usually people are so exhausted they really don’t mind.

I is for internationals and invaders. The US supermaxi Comanche is in Australia with designs on winning the line honors race. So to is the 88-footer Rambler. In all a record 27 international yachts are competing.

J is for jury. A group of appointed officials who enforce the rules of international racing during the Sydney to Hobart. They are needed most years to sort disputes and arbitrate on crashes and rule infringements.

K is for kite. Another name for a spinnaker which is used when a yacht races downwind and is the biggest sail on the boat. Provides the yacht with extra grunt.

L is for line honors winner. The boat which makes it to Hobart in the shortest time. Wild Oats has done this a record eight times — and won the race twice overall. She also owns the race record and is the defending champion.

M is for minnows. The polar opposites of the supermaxis as they are the smallest. The smallest yacht allowed in the Sydney to Hobart is 30 foot but this year the minnow is actually 34 foot.

N is for nautical mile. One minute of latitude or about 1.15 statute miles. this is how distance is measured in sailing.

O is for overall winner. This is decided under a handicapping rule which involves a complicated calculation of such things as size, age, form and results. This allows older yachts to go head to head with newer, fast and bigger boats. Wild Rose is the defending champion.

P is for personal flotation device. A devise which crews must wear. It’s also for Perpetual Loyal, the 100-foot supermaxi being raced to Hobart for charity. Onboard is a celebrity crew which includes former Australian cricketer Michael Clake, Wallaby Kurtley Beale and former Rooster Anthony Minichiello.

Q is for queue. It can be as hectic on the water as it is on the land on Boxing Day, so be patient and mind the queues.

R is for Ragamuffin. The 100 footer is owned by Syd Fischer, at 88 the oldest skipper and sailor in the race. A five-time America’s Cup campaigner he is also a past overall winner of the race.

S is for sunfish. Every sailor’s nightmare. A yacht hits one of these maritime wonders which lurk just below the surface at speed and enormous damage can be caused.

T is for Tony Cable. They say when a sailor does his 25th Sydney to Hobart he goes on the “idiots board”. Sydney sailor Tony Cable is about to embark on a record 50th.

U is for under bare poles. Not a situation you want to be in. When all sail area is taken down due to wild winds and sea conditions. This helps slow the boat down by taking the load off the yacht. A last resort

V is for VHF radio. Every boat must take one as part of extremely strict safely rules tightened in the wake of the deadly 1998 race sounds.

W is for women. This is the 70th anniversary of female participation with two women competing in the second race to Hobart in 1946. There are also a record seven female skippers.

X is for X-ray. This is used on boats to ensure it is ship worthy and safe to sail.

Y is for yacht. Some of the most hi-tech, cutting edge boats in the world contest the race. But little cruisers and slow wooden yachts are all in the wet more for the camaraderie than desire to smash he opposition.

Z is for zephyr. A whisper of breeze. Not good in a race like the Hobart where you want to get south as fast as possible.

Links :

• GeoGarage blog : Rolex Sydney Hobart Yacht Race : who knows what danger lurks at sea? /High speed yacht racing / Sydney to Hobart Yacht Race: Against all elements / Sydney Hobart : Wild Oats XI unveils secret weapons / Sydney-Hobart 2011 : Investec Loyal's against-the-odds victory closest in 28 years / Sailing across the years

US NOAA layer update in the GeoGarage platform

21 nautical raster charts updated

see GeoGarage News

Christmas islands

Christmas Island is a small territory of Australia located in the Indian Ocean,

2600 kilometres (1600 mi) northwest of Perth in Western Australia,

500 kilometres (300 mi) south of Jakarta, Indonesia, and 975 km ENE of the Cocos (Keeling) Islands.

 Christmas island (AUS) bathymetry (source QPS)

Detail an East Indies map (1660) by Pieter Goos showing Christmas Island 
This small section of the map shows the location of Mony, now called Christmas Island.
It is the first time Christmas Island appears on a map.

This is the 'Christmas island' we know on the Territory of Australia, famous for the red crabs migration. (see video)

So named because of its discovery on Christmas Day in 1643, Christmas Island became a territory of Australia in 1958 after spending a number of years under British sovereignty.

The island is primarily rainforest, and 63% of the Island has been designated a national park.

But actually, it turns out that there are actually two Christmas Islands!

Wjo knew the other one ?
Kiritimati aka Christmas Island (Part of the Line Islands, a district of Kiribati)

Kiribati is a country comprised of 33 coral atolls in the Pacific Ocean, including three island groups: the Gilbert Islands, the Line Islands, and the Phoenix Islands.

The Line Islands, where Kiritimati is located, can be found in the central Pacific Ocean, south of Hawaii. 

Kiritimati (where the ‘ti’ combinations are pronounced as ‘s’) is the world’s largest coral atoll.

The island was discovered on Christmas Eve in 1777 by explorer James Cook, thus the reason for the island’s festive name.
A fun fact about the country of Kiribati: it is the only country in the world to fall into all four hemispheres (northern, southern, eastern, and western).

Kiritimati (formerly spelt Christmas)
for the island forming part of Kiribati in the central Pacific Ocean

 Kirimati bathymetric map

 1777 Chart of Christmas Island (Kiritimati)

HoloLens ocean discovery app: past, present & future

From Microsoft by Phil Pauley

The Ocean Discovery App is a unique educational experience that would make the deepest ocean accessible to everyone with access to a HoloLens kit.

The Ocean

The ocean is the lifeblood of our planet, yet most people have a limited understanding of its importance to us.
Despite covering nearly three-quarters of Earth’s surface, 95% of the ocean is unexplored.
We know of around 230,000 marine species, but it’s estimated that there are over 2 million down there, waiting to be discovered!
The ocean is what makes Earth so unique within our solar system, yet we know more about the surfaces of the Moon and Mars than we do about our ocean and the marine life therein.

The Experience

In a classroom setting or at home, for example, the HoloLens Ocean Discovery app would create a three-dimensional holographic cut-away model of an area of ocean, stretching from surface to seafloor.
By zooming in and out of this hologram, people could visualize the ocean in unprecedented detail.
Learners could adjust different aspects of the model—for example, zoom into different ocean depth zones—and interact with rarely seen marine life right before their eyes.
A series of responsive visual sequences could show the viewer how the geology and biology of the ocean interact with the ebb and flow of tides and currents.

Additional, fun and immersive experiences could include a wall transforming into a virtual theater, with holograms of marine creatures emerging from it and swimming towards the viewer.
Users of the app could become divers, combing sunken shipwrecks for hidden treasure, or could experience exploring the intricacy of a coral reef ecosystem.
These types of interactions could be invaluable to aquariums and marine centres.

Immersive experiences within the app would cover topics such as ancient marine life, undersea exploration, marine biology, geology, seismic monitoring for tsunami risk, the tracking of weather patterns and hurricanes, the impact of climate change and acidification on coral reefs, marine archaeology, fisheries, renewable energies and much more.
New topics could be added into the app over time and in response to demand.

Potential Partners

In an effort to communicate the impact of emerging technologies, the Ocean Discovery HoloLens app could feature subsea ocean exploration, marine renewable energy innovations and high-resolution seabed mapping that will be developed over the next decade.

Alongside the home and educational version of the app, a professional version could be developed for use within international organizations that work at sea, or have commercial interests in the ocean. Various training programmes could help prepare qualified specialists in a variety of fields (academic, industrial, scientific and military) to successfully decrease environmental damage to the ocean whilst maximizing its positive impacts.

A preliminary Ocean Induction course could cover a basic introduction to geology and biodiversity, with input from satellite observation data and include the importance of the ocean in Earth’s natural cycles, such as the role it plays in regulating the atmosphere and weather patterns.

Why Now?

Although there is some movement to recognise the importance of the ocean, more needs to be done.
As a source of global economic growth; commerce, food, medicine, energy, and as a carbon sink and regulator of climate change, we must share and increase our knowledge.
The Ocean Discovery HoloLens app could tie in with any number of marine organizations and forthcoming initiative on ocean governance.

More attention will be given to the ocean following the historic Paris agreement, the final document of which noted:
“the importance of ensuring the integrity of all ecosystems, including oceans, and the protection of biodiversity…”

If you appreciate the Ocean and the biodiversity it supports, please vote for this idea now by clicking the star icon !

Hacked at sea: Researchers find ships’ data recorders vulnerable to attack

A voyage data recorder recovery capsule aboard a container ship.

Some VDRs may be an easy target for hackers--or crew members who don't want what they've done to be recorded.
photo : Hervé Cozanet

From Ars Technica by Sean Gallagher

When the freighter El Faro was lost in a hurricane on October 1, one of the goals of the salvage operation was to recover its voyage data recorder (VDR)—the maritime equivalent of the "black box" carried aboard airliners.
The VDR, required aboard all large commercial ships (and any passenger ships over 150 gross tons), collects a wealth of data about the ship's systems as well as audio from the bridge of the ship, radio communications, radar, and navigation data.
Writing its data to storage within a protective capsule with an acoustic beacon, the VDR is an essential part of investigating any incident at sea, acting as an automated version of a ship's logbook.

Sometimes, that data can be awfully inconvenient.
While the data in the VDR is the property of the ship owner, it can be taken by an investigator in the event of an accident or other incident—and that may not always be in the ship owner's (or crew's) interest.
The VDRs aboard the cruise ship Costa Concordia were used as evidence in the manslaughter trial of the ship's captain and other crewmembers.
Likewise, that data could be valuable to others—especially if it can be tapped into live.

It turns out that some VDRs may not be very good witnesses.
As a report recently published by the security firm IOActive points out, VDRs can be hacked, and their data can be stolen or destroyed.

The US Coast Guard is developing policies to help defend against "transportation security incidents" caused by cyber-attacks against shipping, including issuing guidance to vessel operators on how to secure their systems and reviewing the design of required marine systems—including VDRs.
That's promising to be a tall order, especially taking the breadth of systems installed on the over 80,000 cargo and passenger vessels in the world.
And given the types of criminal activity recently highlighted by the New York Times' "Outlaw Ocean" reports, there's plenty of reason for some ship operators to not want VDRs to be secure—including covering up environmental issues, incidents at sea with other vessels, and sometimes even murder.

IOActive researchers looked specifically at the Furuno VR-3000, a VDR that was involved in a case in 2012 where data for a period during which Italian marines aboard a freighter fired upon an Indian fishing vessel "mysteriously" corrupted before investigators could access it.
The marines, who were embarked aboard the freighter Enrica Lexie, claimed that they were in international waters and believed the fishermen to be pirates.
The data that could have proven their location, along with communications data, was lost.

The VR-3000's Data Recording Unit is essentially a Linux-based personal computer with little in the way of security hardening.
Other manufacturers use various industrial, real-time operating systems.
But at least it's more secure than some of the other VDRs sold by Furuno.
In another incident with a different, Windows XP-based VDR in 2012, data was corrupted when a crewmember on a Singapore-flagged ship inserted a USB drive into a port on the VDR—causing it to be infected with malware and for voice and navigation data to be overwritten.
(No, that wasn't a typo: it was a Windows XP-based black box.)

Windows XP is embedded in a variety of hardware at sea.
Furuno's XP-based VX2 system is used in GPS systems, auto-pilots, satellite weather terminals, and Automatic Identification System (AIS) transponders used to provide vessel tracking data.
And many of these systems use standard Ethernet local area networks to connect to navigational systems—as well as to PCs that provide access to the stored data.

The network of devices connected to a voyage data recorder system.

(Furuno)

IOActive did a deep analysis on the VR-3000 and found a number of vulnerabilities, including:
Weak encryption of voice data files using an embedded, shared password.
Vulnerabilities in software services that allowed remote attackers to execute code on the data recording unit with root privileges, including the ability to "delete certain conversations from the bridge, delete radar images, or alter speed or position readings."
The VDR could also be turned into a remote bug to spy on the crew of a ship through its attached microphones.

To execute remote attacks on the VDR, the attacker only needed access to the network.
Since many VDR systems use Ethernet and sit on the same network as satellite communications systems (some of which are known to be vulnerable to attacks), there are a number of potential ways attackers could breach the security of the VDR while not being aboard.
Terrorists, pirates, hostile state actors and others could pinpoint the location of ships of interest and then listen to the conversations of crewmembers as well as their radio calls.

IOActive revealed these vulnerabilities to the Department of Homeland Security's Industrial Control Systems Computer Emergency Response Team (ICS-CERT) and Japan's CERT Coordination Center (JPCERT/CC) over a year ago.
Furuno was notified as well, but it promised only to patch the problem "sometime in 2015," according to the IOActive report.
There's no word on whether the patches have been distributed to ship operators.

Links :

• Hacked : Ships Are Vulnerable to Hackers and Sabotage
• Softpedia : Cargo Ship Black Boxes Deemed Vulnerable, Prone to Hacking
• Darkreading :  Sea Craft Voyage Data Systems Vulnerable To Tampering, Spying
• Motherboard : Pirate Hackers Can Easily Spy on Ships Through Insecure 'Black Boxes'

Could shipwrecks lead the World to war?

Eric Nyquist

From NYTimes by Peter B. Campbell

Archaeology has long been exploited as a political tool.
Hitler used artifacts and symbols to manufacture a narrative of Aryan racial superiority.
The Islamic State proves its zealotry by destroying evidence of ancient history.
Underwater archaeology — the world of shipwrecks and sunken cities — has mostly avoided these kinds of machinations, though.
Since no one lives beneath the sea, leaders haven’t found many opportunities for political gains from archaeological sites there.

That is, until now.

In the past few years, politicians in Canada, Russia and China have realized that they can use shipwrecks on the sea floor to project their sovereignty into new maritime territories.
And this politicized abuse of science is putting the world on a path toward conflict.

For decades, global powers have been engaged in a race to exploit lucrative marine resources, from oil to fisheries to control of strategic waterways.
But they have faced a challenge: How can a country claim new territory despite the restrictions of the United Nations Convention on the Law of the Sea?
It turns out that “historical ties” to resource-rich regions can conveniently help to contravene international law.

 H.M.S. Erebus

Last year, Canada announced the discovery of H.M.S. Erebus, Sir John Franklin’s flagship, which disappeared during a Northwest Passage expedition in 1845.
Stephen Harper, then the prime minister, personally announced the discovery.
His government and its allies provided significant funding for the research.
But Mr. Harper isn’t just a history buff; his interests are practical.

Global warming has made the Northwest Passage more accessible to shipping, which could be an economic windfall for Canada if the government is able to demonstrate sovereignty and charge other countries a transit fee.
“Franklin’s ships are an important part of Canadian history given that his expeditions, which took place nearly 200 years ago, laid the foundations of Canada’s Arctic sovereignty,” Mr. Harper said.

China has been similarly aggressive.
While the South China Sea has historically been shared between China and its neighbors, in the past year Beijing has begun building artificial islands to claim the sea as its own territorial waters. Archaeology laid the groundwork for this belligerence: Starting in 2007 China began archaeological excavations and opened several shipwreck museums, each costing tens of millions of dollars.
In 2014, China’s government launched a $60 million archaeological research vessel to find shipwrecks in the South China Sea.

Archaeologists rewarded the investment by locating more than 120 shipwrecks inside the contested areas.
China’s deputy minister of culture, Li Xiaojie, put it bluntly: “Marine archaeology is an exercise that demonstrates national sovereignty.”

Russia has followed suit.
In 2011, when he was prime minister, Vladimir V. Putin made headlines by retrieving two ancient ceramic jars from a shipwreck at Phanagoria, the ancient Greek city that is 10 miles from Crimea. The media cast it as a publicity stunt, but alarm bells sounded within the archaeological community. Mr. Putin’s political allies had invested $3.5 billion in research at Phanagoria, a submerged harbor with Roman-era shipwrecks.
And while Phanagoria was the site of Greek colonies, Russian nationalists have adopted its ancient kings as proto-Russians.

Russia's Vladimir Putin takes dive in submersible, stirs up Ukrainian anger

When Mr. Putin made his speech announcing that Russia had annexed Crimea in March 2014, he justified the move in part based on historical ties to the peninsula.
“This is the location of ancient Khersones, where Prince Vladimir was baptized,” he said.
The annexation added tens of thousands of square miles to Russia’s Black Sea maritime zone.
And this summer a Russian expedition began a major underwater archaeology survey off Crimea’s Sevastopol, a region rich in oil and gas.

For politicians, natural resources are the ends and shipwrecks are the means.
But archaeology rarely fits simple narratives.
In fact, archaeology often demonstrates our shared human past.
Until 10,000 years ago, the disputed regions in the South China Sea were dry land.
Taiwanese archaeologists have located submerged Stone Age remains there that point to a common ancestry of all the region’s inhabitants.
Native peoples traversed the Northwest Passage for thousands of years before Sir John Franklin arrived.
In his annexation speech, Mr. Putin cited Vladimir the Great, the 10th-century Viking conqueror and adopted progenitor of Russian identity, but the president neglected to mention that Vladimir the Great ruled from Kiev, in modern-day Ukraine.

 The Map of South and East Ocean Sea Routes was drawn in between 1712-1721 by Qing (Ching) Dynasty Fujian (Fuchien) Province Navy Commander Shi Shibiao, the son of a famous Qing Dynasty imperial officer.

This map clearly shows the sea routes, time, and descriptions from Chinese coastal ports to Japan, Laos, Vietnam, Indonesia, Brunei, Cambodia and the Philippines.

On this map, the locations and names of the Southern Sea Islands (Nanhai Zhudao) are very accurate. The map shows Chinese sovereignty over the South China Sea islands (including Nansha Islands, Xisha Islands, Zhongsha Islands and Dongsha Islands).

Archaeologists accept government funding because the world’s cultural resources are disappearing as a result of looting and treasure hunting.
But archaeology in the service of nationalism results in bad science.
What happens when China discovers ancient Vietnamese ships in the South China Sea?

And in Canada we already have a troubling example:
Against accepted preservation practices, Canada gave permission for the removal of the wreck of the explorer Roald Amundsen’s ship Maud to Norway, quietly eliminating a politically messy reminder that a Norwegian was the first Westerner to successfully navigate the Northwest Passage.

The underwater discoveries in Phanagoria, the South China Sea and the Northwest Passage are important scientific discoveries.
The problem is not with the archaeologists conducting quality research, but with the politicians spinning evidence to suit their desires.
The reality is that these are overt land grabs using manufactured historical claims.
Citizens around the world would be wise to tell politicians to stop abusing the past for present-day ambitions.

Links :

• WSJ : Chinese Territorial Strife Hits Archaeology
• The Diplomat : Archaeology and the South China Sea
• GeoGarage blog :The new Silk Road: A visionary dream for the 21st century / Mystery of island visited by 15th Century Chinese explorer Zheng He now solved / China plunges into ocean research / China unfettered: Redefining the rules of the seas / Restored map reveals early Arabian trade links with China / Canada searches for Sir John Franklin’s rescue ship / Canada finds British vessel that vanished on doomed North-West Passage expedition in 1840s

China cracks down on politically incorrect maps

 A Chinese-made globe depicting the nine-dash line, which is disputed by the Philippines, 

on sale in Manila, Philippines.

To justify its claims over territory in the South China Sea,

China uses historical maps with the so-called “nine-dashed line” as evidence.

Photo: Alan Robles

From Atlantic CityLab by Linda Poon

China releases new rules on map services :
getting caught with the “wrong” maps can result in a hefty fine of up to $31,000—or criminal charges.

When it comes to maps, China isn’t messing around.
Starting next year, you don’t want to be caught with the “wrong” maps—that is, maps containing content “that endangers the country's sovereignty, safety and interests,” according to a statement by China’s government mapping official Le Weibin.
In an effort to “boost” the mapmaking industry—and clamp down on maps that run counter to the government’s stance on issues like Taiwan’s independence and the territorial dispute over the South China Sea—China announced new regulations earlier this year on the creation, distribution, and publication of both print and online maps.

 South China Sea, dangerous ground & unsurveyed grounds (GeoGarage / NGA)

The government will be monitoring maps for violations like “errors in compilation” and “leaks of secret geographic information and personal information,” according to China’s official state media, Xinhua.
Also included in this new set of regulations, which will replace mapping laws drawn up in 1995, is a section dedicated to regulating the fairly young industry of online mapping.
It requires all online mapping data to be hosted by servers inside the country, and all GPS providers to obtain a cartography certificate.
Details remain fairly vague for now, but CCTV News reports that violators can face up to 200,000 yuan, or about $31,000, in fines.
Businesses can also have their licenses suspended or revoked.
If the violation is deemed serious enough, they can even find themselves booked on criminal charges.

South China Sea islands map with nine dash dots (source : archives Taiwan )

other maps

But the tough stance on maps isn’t new.
The Los Angeles Times reported in October that customs officials at airports often go through travelers’ belongings looking for anything pushing back on China’s official political stances.
Scholars, expatriates, and reporters alike have had to abandon maps, globes, and books that rendered Taiwan in a different color than the one used for China or that failed to indicate disputed islands in the East China Sea* as the Diaoyu Islands.

That’s because to China, maps are more than just a navigational tool, especially as tensions rise between the country and its neighbors over those islands.
In a statement released earlier this week, the state council declared maps politically, scientifically, and legally important, “as they draw the territory of a country, directly reflecting its national sovereignty and political views.”

Paracel islands in the GeoGarage platform (NGA charts)

The new ordinance will also cover online mapping.

To help with monitoring, online maps are required to set up their server inside of the country

and must acquire an official certificate. 

In July, Google Maps came under fire from the Chinese government for removing the Chinese name for the Scarborough Shoal, a rich fishing ground in the South China Sea that both China and Philippines lay claim to.
The move from Google came after persistent petitioning from Filipino fishermen, who said the Chinese name effectively gave credibility to China’s claims.

China has also used historical maps reinforce its claim to the Scarborough Shoal.
Those maps include the so-called “nine-dashed line,” which was first drawn in 1947 by the Nationalist government.
And while the history of how this line came to exist is murky—even to Chinese officials—China declared it as sufficient evidence of the country’s ownership of the islands, according to Reuters.
“The dotted line of the South China Sea indicates the sovereignty of China over the islands in the South China Sea since ancient times and demonstrates the long-standing claims and jurisdiction practice over the waters of the South China Sea,” Chinese officials wrote in a statement to the U.S. embassy in Beijing.

In an interview with the Los Angeles Times, an expert on Chinese history noted that maps were a sign of legitimacy:

"Regimes that are anxious about their legitimacy fetishize the signs of legitimacy," said Tim Brook, a professor of Chinese history at the University of British Columbia and author of "Mr. Selden's Map of China," a book about an East Asia map from the 1600s. "So one of the signs of legitimacy is a map—there you are one color, your borders are all drawn properly and you look like a proper state."

Links :

• Fortune :  China Tightens Control of Online Maps
• Shangaiist : Google Maps removes Chinese name for disputed Scarborough Shoal in South China Sea
• GeoGarage blog :China's fishermen explain why they think the sea is theirs / Philippines uses 18th-century English aristocrat's map to claim disputed islands / Manila says China starts dredging at another reef in disputed waters / Troubled waters: the South China Sea dispute / China's lawful position on the South China Sea / US: China failed to clarify 9-dash line with law /Lies, damned lies and maps / New map boosts China's maritime claims / Battle of the South China Sea charts / How the Selden Map rewrote History / China's line in the sea / Japanese government urges boycott of Google Maps over disputed islands / Ancient map irrefutable evidence that the Diaoyu Islands, the ancient belongs to China / Vietnam demands China removes illegal EEZ dotted line on online map / Restored map reveals early Arabian trade links with China / The Law of the Seas and the Spratly Islands dispute / Scarborough Shoal : long history of Philippines management / How the U.S. maps the World’s most disputed territories / Philippines, China commit to diplomacy to end Scarborough standoff

The beauty of sailing

NZ Linz update in the GeoGarage platform

 11 nautical raster charts updated

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